WO2020193544A1

WO2020193544A1 - Method for operating a drive unit of a vehicle, and drive unit

Info

Publication number: WO2020193544A1
Application number: PCT/EP2020/058148
Authority: WO
Inventors: Kiarash SABZEWARI; Klaus Leipnitz; Roger Pohlmann; Andreas Riedel
Original assignee: Vitesco Technologies Germany Gmbh
Priority date: 2019-03-25
Filing date: 2020-03-24
Publication date: 2020-10-01
Also published as: DE102019204076A1

Abstract

The invention relates to a method for operating a drive unit (1) of a vehicle (F), wherein in a transmission (3) of the drive unit (1), at least one gear (G1 to G4) is automatically engaged, when a roll-away prevention system (PS) for the vehicle (F) is activated.

Description

description

Method for operating a drive unit of a vehicle and drive unit

The invention relates to a method for operating a

Drive unit of a vehicle and a drive unit for a vehicle.

Methods for operating drive units for vehicles, in particular motor vehicles, are generally known from the prior art. Drive units include

at least one drive unit, e.g. B. a

Internal combustion engine, and a transmission. Gear can

be designed for example as a manual gearbox, automated gearbox or automatic transmission.

To secure the vehicle when parking against a

unintentional rolling are especially for

automated transmission and automatic transmission separate

Roll prevention provided. Rolling prevention can be activated directly by the driver or indirectly using electrical aids.

The invention is based on the object of providing a method for operating a drive unit of a vehicle that is improved over the prior art and an improved method

Specify the drive unit for which the

The vehicle is secured against unintentional rolling away.

With regard to the method, the object is achieved according to the invention with the features specified in claim 1.

With regard to the drive unit, the object is achieved by the features specified in claim 9. Advantageous embodiments of the invention are the subject of the subclaims.

In a method according to the invention for operating a

Drive unit for a vehicle, at least one gear is automatically engaged in a transmission of the drive unit when a roll-away prevention for the vehicle is activated.

The process is automated

Roll-away prevention for the vehicle without additional

Locking elements in the transmission possible. Since inserting the

Transmission gear takes place automatically, manual engagement of the transmission gear by a driver is not necessary. By engaging the transmission gear is meant in particular the selection and setting of a gear stage or gear stage.

According to the invention, the drive unit for a vehicle comprises a transmission with at least one transmission gear, one

Input shaft and an output shaft and a switching unit arranged between these, at least one

Drive unit, which can be mechanically coupled to the input shaft, and an output unit, which via the

Transmission can be mechanically coupled to the at least one drive unit, the shift unit automatically engaging at least one of the transmission gears when one

Roll-away prevention for the vehicle is or is activated. The switching unit is for example as a coupling unit, in particular a sliding sleeve, between the input and

Output shaft formed.

For example, in order to automatically engage the at least one transmission gear, at least one is locked in rotation with the

The output shaft of the gearbox connected to the sliding sleeve Coupling unit by means of an actuator unit axially on the

Moving output shaft. The sliding sleeve is used to insert the gear, in which this with a rotation-free on the

Output shaft mounted gear is positively connected. By using a sliding sleeve as part of the coupling unit, the transmission can be designed in a simple and space-saving manner. This also enables a simple

automatic control of the sliding sleeve by means of the

Actuator unit.

According to one embodiment, the actuator unit is electronically controlled by a control unit. The

The control unit is, for example, a transmission control unit and enables the automatic engagement of a transmission gear when the roll prevention is activated. In addition, the

Control unit determine whether the sliding sleeve is brought into a correct position and thus the requested one

Gear is engaged.

The control unit can activate the

Detect roll-away prevention when the actuating element is operated manually or automatically. An automatic activation comes into question, for example, if the vehicle parks independently and then the

Should activate roll prevention. For example, the actuator, for. B. a selector lever moved by a user into a park position. The control unit recognizes this, so that it then generates a control signal to control the actuator unit. Alternatively, it is also possible for the control unit to automatically generate a control signal as soon as the vehicle is stopped and the drive unit, in particular the engine, is switched off. According to one embodiment, the shift fork coupled to the sliding sleeve can be operated by means of the actuator unit

be moved electromechanically or electrohydraulically. For this purpose, the actuator unit comprises, for example, a hydraulic drive or motor with a hydraulic valve which can be electronically controlled by means of the control unit. Alternatively, the actuator unit can also include a motor, for example an electric motor or a motor designed as a mechanical lever arrangement. If only one gear is to be engaged, the transmission input shaft should be positively coupled with the drive unit. Alternatively, the unit can comprise a motor which, for example, actuates the shift fork via a lever arm.

According to a further embodiment, two

Transmission gears automatically engaged at the same time when the roll prevention is activated. This is particularly advantageous when the vehicle is on a slope

is or is turned off. The so-called

Downhill force on the vehicle, which can cause the vehicle to roll away unintentionally. By the

Simultaneous engagement of two gears will be

Gearbox blocked or locked in such a way that rotation of the output shaft is no longer possible. This prevents the vehicle from rolling away.

Embodiments of the invention are explained in more detail below with reference to a drawing.

It shows:

1 schematically shows a drive unit for a vehicle. The only figure 1 shows schematically a drive unit 1 of a vehicle F with a drive unit 2, a

Gear 3 and an output unit 4.

The transmission 3 comprises at least one transmission gear Gl to G4, an input shaft E and an output shaft A and a shift unit S arranged between them

Drive unit 2 is mechanically coupled to input shaft E. The output unit 4 can be mechanically coupled to the at least one drive unit 2 via the transmission 3. The shift unit S is set up to automatically engage at least one of the transmission gears Gl to G4 when a roll-away prevention PS for the vehicle F is or is activated.

In an embodiment not shown, a

Transmission 3 with more than four transmission gears Gl to Gn

be provided.

In addition, the drive unit 1 comprises a

Actuating element 5 and a control unit 6.

The drive unit 2 of the drive unit 1 is a

Internal combustion engine, which is coupled to the transmission 3 by means of the input shaft E. The input shaft E here forms the drive shaft of the transmission 3. The transmission 3 is based on an automated gearbox in which a countershaft V is arranged that runs parallel to an output shaft A of the transmission 3.

The input shaft E and the countershaft V are mechanically coupled to one another by means of a first pair of gears, including the gears ZI, Z2. Im shown

Embodiment, the transmission 3 has four pairs of gears and thus four transmission gears Gl to G4, also referred to as gear stages or gear stages. Alternatively, the transmission 3 can also have fewer than four or more than four transmission gears Gl to G4.

The output shaft A runs coaxially to the input shaft E and is also mechanically coupled to the countershaft V. For this purpose, further gears Z3, Z5, Z7 are arranged on the output shaft A, which are in constant engagement in pairs with further gears Z4, Z6, Z8 arranged on the countershaft V and thus provide different ratios for the transmission gears Gl to G4.

For each pair of gearwheels, one of the gearwheels ZI to Z8 is arranged in a rotationally fixed manner on the countershaft V and the other of the gearwheels ZI to Z8 is arranged on the input shaft E or output shaft A, freely rotating and axially fixed. In the embodiment shown, this is freely rotating

arranged gear ZI is arranged in particular on a section of the input shaft E designed as a hollow shaft. The gear wheel Z2 is fixedly arranged on the countershaft V.

A second pair of gears includes the fixed on the

Layshaft V arranged gear Z4 and the freely rotating on the output shaft A arranged gear Z3, which is formed as a hollow shaft section of the

Output shaft A is arranged.

A third pair of gears includes the fixed on the

Gear Z6 arranged on the countershaft V as well as the gear Z5 arranged freely rotating on the output shaft A. A fourth pair of gears comprises the gear Z8 which is fixedly arranged on the countershaft V and the gear ZI which is arranged freely rotating on the output shaft A.

A first coupling unit Kl is arranged between the freely rotating gears ZI, Z3. Furthermore, a second coupling unit K2 is arranged between the freely rotating gears Z5, Z7.

The coupling units Kl, K2 each include one

Sliding sleeve Kl.l, K2.1, by means of which one of the non-rotating gear wheels ZI, Z3, Z5, Z7 rotatably with the

Output shaft A is connected. The

Sliding sleeves Kl.l, K2.1, for example, one each

Metal ring with a toothing not shown in detail, which is non-rotatably connected to the output shaft A and is arranged axially displaceable on this. Alternatively, instead of a sliding sleeve Kl.l, K2.1, a

Claw coupling be provided.

The coupling units Kl, K2 are each by means of

Actuating element 5 actuated, by means of which a driver of the vehicle F can manually select the transmission gears Gl to G4. For this purpose, the actuating element 5 is, for example, a selector lever, a switch, a lever and / or a button.

Between the actuator 5 and the

Coupling units Kl, K2, a control unit 6 and an actuator unit 7 are also arranged. Using the

Control unit 6 also enables automated selection of a desired or required transmission gear Gl to G4.

An actuation of the actuating element 5 is recognized by the control unit 6, which a corresponding Control signal for controlling the actuator unit 7 is generated. The actuator unit 7 comprises two motors M1, M2, each of which actuates a switching unit S. In this case, a first motor Ml actuates, in particular adjusted, the first coupling unit Kl and a second motor M2 the second coupling unit K2. The

Motors M1, M2 are each designed as electromechanical and / or electrohydraulic motor units.

For example, the motors Ml, M2 each include a piston, which by means of an electronically controllable hydraulic valve with pressurized

Hydraulic fluid is applied. As an alternative, the motors M1, M2 can each also comprise an electronically controllable mechanical lever arrangement.

The motors Ml, M2 are each one in detail

Shift fork 8 with a sliding sleeve Kl.l, K2.1 der

corresponding coupling unit Kl, K2 connected. The

Shift forks 8 are each, for example, rod-shaped and with one end to the respective motor Ml,

M2 connected. Based on that with the motor Ml, M2

connected end runs a first section of the

Shift forks 8 each parallel to the output shaft A. A second section of the shift forks 8 runs perpendicular to the first section in the direction of

Output shaft A. At an opposite end of the

Shift forks 8 each have a guide element 8.1, which engages in the associated sliding sleeve Kl.l, K2.1 and takes it along when the shift fork 8 moves.

In the embodiment shown, both are

Coupling units Kl, K2 in an open state

shown. That is, the transmission 3 is in a neutral position, with none of the shiftable positions

Gears ZI, Z3, Z5, Z7 with one of the Sliding sleeves Kl.l, K2.1 and thus not positively connected to the output shaft A. A power flow between the drive unit 2 and the output shaft A is thus interrupted.

Starting from the input shaft E, the first

Gear pair the countershaft V driven. By the

Shifting the following transmission gears Gl to G4, a torque is transmitted from the countershaft V to the output shaft A. This torque is then applied to the

Transfer output unit 4, which, for example, a

Differential gear includes, the final drive shafts for drive wheels of the vehicle F, z. B. front-wheel drive wheels.

To insert a gear Gl to G4, the

corresponding shift fork 8 is controlled by means of the actuator unit 7. From a control of the shift fork 8

results in an axial displacement of the

Sliding sleeve Kl.l, K2.1 on the output shaft A in the direction of the gear ZI, Z3, Z5, ZI assigned to the selected transmission gear Gl to G4.

A sliding sleeve Kl.l, K2.1 is for two

Transmission gears Gl, G2 or G3, G4 are responsible. To the

Gears ZI, Z3, Z5, Z7 are each not shown formations arranged with the teeth of the

Corresponding sliding sleeves Kl.l, K2.1. This enables positive engagement of the sliding sleeve Kl.l, K2.1 in the corresponding gear ZI, Z3, Z5, ZI. As a result, the gear ZI, Z3, Z5, Z7, which is positively connected to the sliding sleeve Kl.l, K2.1, is non-rotatably connected to the output shaft A. The other gears ZI, Z3, Z5, Z7, however, are rotatably mounted on the output shaft A. When the sliding sleeve Kl.l, K2.1 is positively connected to the corresponding gear ZI, Z3, Z5, Z7, a

Speed of the corresponding gear ZI, Z3, Z5, Z7 adapted to a speed of the output shaft A. Such a one

The speeds are synchronized, for example, by means of a synchronizer ring which is arranged on the coupling unit K1, K2, but is not shown here, through which friction between the corresponding

Gear ZI, Z3, Z5, Z7 and the output shaft A takes place.

If the speeds are synchronized, the slides

Sliding sleeve Kl.l, K2.1 over the corresponding

Gear ZI, Z3, Z5, Z7 and provides a mechanical connection between the input shaft E and the

Output shaft A. When the vehicle F is in operation, a force is thus transmitted from the drive unit 2 to the output unit 4.

If the vehicle F is parked and an insertion is made

Roll away prevention PS triggered, for example by

Actuation of a corresponding actuating element 5 in a corresponding release or activation position is automatically at least one of the

Gear gears Gl to G4 engaged. The engagement of one of the transmission gears Gl to G4 to engage the roll-away prevention PS secures a mechanical locking of the vehicle F against rolling or rolling up to a predetermined one

Limit even if a parking brake is released.

For this purpose, one of the sliding sleeves Kl.l, K.2.1 is activated by means of the actuator unit 7 as soon as the roll-away prevention PS is activated. The insertion of the roll away prevention PS can, for example, by the driver by actuating the Actuating element 5 in a release or

Activation position can be activated electronically.

The control unit 6 recognizes the release or

Activation position of the actuating element 5 and generates a corresponding control signal for controlling the

Actuator unit 7, which in turn controls one of the motors M1 or M2. As already described, the

Motors Ml, M2 moves the shift forks 8, which the

Sliding sleeves class 1, K2.1 according to the selected

Transmission gear Gl to G4 axially on output shaft A.

move. Thus, when the

Roll-away prevention PS, one of the transmission gears Gl to G4 is automatically inserted in the transmission 3. This corresponds to a

Engaging a transmission gear Gl to G4 by the driver in a manual transmission.

When one of the gears Gl to G4 is engaged, one of the gear pairs is connected to the output shaft A in a rotationally fixed manner. If the drive unit 2 is switched off, the rotates

Input shaft E is not and therefore not the

Output shaft A. Since no power is transmitted to the output unit 4 and thus also not to the vehicle wheels, the vehicle F remains stationary up to a predetermined limit value and is secured against rolling away up to this limit value.

Alternatively, two gears can be engaged at the same time, whereby the transmission 3 is safely blocked and a parking lock WS of the vehicle F is made possible. For this purpose, the parking lock WS is triggered or activated,

for example by actuating the same

Actuating element 5 in a different release or

Activation position or another Actuating element 5, at least two of the gears Gl to G4 are automatically engaged in the transmission 3. The engagement of the two transmission gears Gl to G4 for engaging the parking lock WS of the vehicle F enables the transmission 3 to be locked and the locking mechanism to be secured

Vehicle F against rolling away, even if one

Parking brake is released.

The output shaft A can no longer rotate here, so that a power transmission to the output unit 4 and thus to the vehicle wheels is prevented. This is

particularly advantageous when the vehicle F is parked on a slope and the so-called downhill force acts on the vehicle F. Due to the blocking of the

Transmission 3 counteracts the downhill force with a correspondingly greater force, so that the vehicle F is prevented from rolling away unintentionally.

Claims

1. A method for operating a drive unit (1) for a vehicle (F), wherein in a transmission (3) the

Drive unit (1) at least one gear (Gl to G4) is automatically engaged when a

Roll-away prevention (PS) is activated for the vehicle (F).

2. The method of claim 1, wherein the automatic

Insertion of the at least one gear (Gl to G4) axially on at least one sliding sleeve (Kl.l, K2.1) of a coupling unit (Kl, K2) connected to an output shaft (A) of the gearbox (3) in a rotationally fixed manner by means of an actuator unit (7) the output shaft (A) is moved.

3. The method of claim 2, wherein the

Sliding sleeve (Kl.l, K2.1) for the automatic engagement of at least one gear (Gl to G4) with a non-rotating on the output shaft (A)

Gear (ZI, Z3, Z5, Z7) is positively connected.

4. The method of claim 2 or 3, wherein the

Actuator unit (7) from a control unit (6)

is controlled electronically.

5. The method according to claim 4, wherein the control unit (6) recognizes an actuation of an actuating element (5) when the roll-away prevention (PS) is activated.

6. The method of claim 5, wherein to activate the

Roll-away prevention (PS) the actuating element (5) is moved into an activation position by a user.

7. The method according to any one of claims 2 to 6, wherein one with the sliding sleeve (Kl.l, K2.1) coupled

Shift fork (8) by means of the actuator unit (7)

is moved electromechanically or electrohydraulically.

8. The method according to any one of the preceding claims, wherein two transmission gears (Gl to G4) are automatically engaged at the same time when a parking lock (WS) is activated.

9. Drive unit (1) for a vehicle (F), comprising

- A gear (3) with at least one gear (Gl to G4), an input shaft (E) and one

Output shaft (A) and a switching unit (S) arranged between them,

- At least one drive unit (2) which is mechanically coupled to the transmission (3) by means of the input shaft (E), and

- an output unit (4) which can be mechanically coupled to the at least one drive unit (2) via the gear unit (3),

wherein the switching unit (S) at least one of the

Transmission gears (Gl to G4) are automatically engaged when a roll-away prevention (PS) for the vehicle (F) is or is activated.